Anastomosis is a procedure by which two hollow tissue structures are joined together. More particularly, vascular anastomosis is a procedure by which two blood vessels within a patient are surgically joined together. Vascular anastomosis is performed during treatment of a variety of conditions including coronary artery disease, diseases of the great and peripheral vessels, organ transplantation, and trauma. In coronary artery disease (CAD) an occlusion or stenosis in a coronary artery interferes with blood flow to the heart muscle. Treatment of CAD involves the grafting of a vessel in the form of a prosthesis or harvested artery or vein to reroute blood flow around the occlusion and restore adequate blood flow to the heart muscle. This treatment is known as coronary artery bypass grafting (CABG).
In the conventional CABG, a large incision is made in the chest and the sternum is sawed in half to allow access to the heart. In addition, a heart-lung machine is used to circulate the patient's blood so that the heart can be stopped and the anastomosis can be performed. In order to minimize the trauma to the patient induced by conventional CABG, less invasive techniques have been developed in which the surgery is performed through small incisions in the patient's chest with the aid of visualizing scopes. In both conventional and less invasive CABG procedures, the surgeon has to suture one end of the graft vessel to the coronary artery and the other end of the graft vessel to a blood-supplying artery, such as the aorta. The suturing process is a time consuming and difficult procedure requiring a high level of surgical skill. In order to perform the suturing of the graft to a target vessel such as the coronary artery or the blood supplying artery, a surgeon holds the edges of the incision in the target vessel with one handle and holds a needle in the other hand for suturing, or an assistant may hold the edges of the incision in the target vessel while a surgeon makes small stitches as close as possible to the edges of the incision. This suturing requires a high degree of precision and is quite time consuming. In addition, during conventional CABG procedures blood flow at the anastomosis site is stopped during suturing. This prevents bleeding from the incision site but also prevents blood from reaching a portion of the heart muscle served by the vessel. Further, during off-pump CABG procedures a side clamp or other device may be used to isolate a portion of the wall of the aorta to which a graft vessel is sutured. The use of a side clamp or similar device can cause emboli to detach from the wall of the aorta and enter the bloodstream, which is undesirable.
Accordingly, it would be desirable to provide a vascular anastomosis system that allows the tissue at the anastomosis site to be controlled during suturing or other connection of the graft and target vessels. It would also be desirable to provide a vascular anastomosis system that allows the connection of a graft vessel to a target vessel prior to making an incision in the target vessel which allows blood flow between the target vessel and the graft vessel.